Some modules don't accept either RTD or thermocouples.Some can be used for current/ voltage only and some other modules accept voltage/current/ certain types of RTDs and thermocouples.

So, modules that measure voltage and current can't accept all types of RTDs and thermocouples.

For example, the module6ES7 331-7KF02-0AB0 can be used for various voltage and current measurements.This module could also be used for certain types of RTDs and thermocouples.For example,if you have PT-1000 or thermocouple type T, you wouldn't be able to use this module.

But RTD module (6ES7 331-7PF01-0AB0) accepts all types of RTDs and nothing else with 16 bit resolution.It's more specified for RTDs with higher accuracy than any other module that accepts RTDs (certain types).

It's the same for thermocouple module (6ES7 331-7PF11-0AB0) that accepts all types of thermocouples and nothing else with 16 bit resolution.

To understand more about analog modules,take a look atchapters 4,5 and 6 inS7-300 module data